Locally greatly different flow and pressure conditions frequently occur in the distribution chamber arranged upstream of the injection elements due to the design, e.g., as a consequence of lateral admission through a line. Furthermore, high velocity components may occur at right angles to the direction of injection, i.e., highly unfavorable conditions may occur in the inlet area of the injection elements. The consequences are, among other things, a reduced propellant throughput, an unsatisfactory spray pattern, as well as deviations from one element to the next despite identical geometry. The consequence with respect to the engine is usually a loss of power, and harmful vibrations of the combustion chamber, nonuniform thermal loads/deformations, etc., may occur as well.
Such a rocket combustion chamber, which has an injection head with a simple distribution chamber (propellant collection chamber 4) supplied with propellant from one side, is described in, e.g., DE-AS 12 90 375. See especially FIG. 2 in this connection.
U.S. Pat. No. 3,194,012 pertains to the problem of a uniform velocity distribution in both distribution chambers of the injection head for the purpose of optimal cooling. The distribution chambers are divided into helical channels with adapted flow cross section pattern. This also has the drawback that high velocity components occur at right angles to the injection elements.
A rocket injection head, which is designed for high mechanical strength and uniform propellant distribution, has been known from DE-PS 977 508. Among other things, a plurality of radially arranged pipes, from which separate holes lead to every individual injection element, are provided for this purpose. When bearing the fact in mind that several hundred injection elements are present in large engines, it will soon become clear that the enormous expense of manufacture is not at a meaningful/acceptable ratio to the benefit. In addition, the many small, long channels lead to high and again locally different pressure drops. See especially FIGS. 2 and 3.